Voltage transformers (VTs), which are quite different from distribution and transmission transformers, play an important role in power distribution systems. These transformers are used to measure the voltage by stepping down the high voltage to a manageable value for voltmeters and energy meters. Additionally, they control the supply by sending the signal to protective relays, which come into action when a highly irregular voltage or fault is detected. Hence, the significance of these transformers is quite high in power substations, transmission lines, and electrical grids. Whether it is an oil-immersed voltage transformer or a dry type, it has a certain range of lifespan, after which it needs to be replaced.
If these are not replaced in due time, it poses the risk of catastrophic failure that may damage other devices also, safety risks, downtime and economic burden. In this blog, we will discuss the signs you need to replace your voltage transformer.
Signs To Watch For in Voltage Transformers
Electrical Signs
- Inconsistent Voltage: If the voltage distributed to the voltmeter is inconsistent and erratic, it may damage the voltmeter. Therefore, it should be checked for irregularities.
- Frequent Tripping: If the protective relay trips frequently, it indicates there may be a fault in VT.
- False Signaling: If the fault signal from the transformer to the protective relay is frequent or wrong, there is a sign of a problem in the voltage transformer.
Visual Signals
Here are the visual signs that indicate the damage and degradation of voltage transformers:
- Burn marks: If the parts of the transformer show bulging, or burn marks, it indicates overheating or probable damage.
- Wear Signs: Check for the signs of cracks, dents, or too much rust due to wear and harsh performing conditions.
- Leakages: Oil or fluid leakages indicate damage or performance failure of protective and insulating parts.
Sound Inspection
While it makes little or ow hum sound under ideal conditions, the ratting, and buzzing sounds indicate a problem. Unusually high noise also direct towards impending failure and ageing of voltage transformer.
Maintenance Test Indicators
Companies like Macro Plast Transformers conduct annual maintenance test which covers a long series of inspections, repair works, and analysis. If these tests suggest that the transformers service life is coming to an end, then there should be no doubt about it.
Age of Voltage Transformer
Depending upon the design of the voltage transformer, the lifespan can vary. The oil-immersed voltage transformer has an average lifespan of 20-30 years, while the dry type has 35-40 years.
Conclusion
The voltage transformers are vital to power distribution as they measure and help in controlling the supply voltage from power distribution systems. To check the signs of ageing and the need for its replacement, one needs to look for visual signs, audio signs, electrical factors, and the results from maintenance tests. For repair or replacement of voltage transformers, one can refer to us at Macro Plast Transformers. We have expertise in manufacturing and repairing different voltage transformers with assured success.
